Every few years, some enterprising individual hits upon the idea of taking Sherlock Holmes, the legendary detective character created by Sir Arthur Conan Doyle, and messing around with the format that has served it well for all these years in the hopes of presumably making it more attractive and accessible to younger and hipper audiences--these experiments have ranged from attempts in the 1940’s to relocate the characters to then-contemporary times so that he and longtime companion/chronicler Dr. James Watson could outwit Nazis to broad comedies like the Dudley Moore-Peter Cook take on “The Hounds of the Baskervilles” and the Michael Caine-Ben Kingsley farce “Without a Clue” to the unspeakable 1985 effort “Young Sherlock Holmes,” which answered the never-asked question “What would have happened if Holmes and Watson met each other in boarding school and found themselves trapped in a “Temple of Doom” knockoff?” Although some of these attempts to rejuvenate the character and the franchise had their entertaining moments (though I should stress that “Young Sherlock Holmes” is most assuredly not among them), none of them were particularly effective in the long run because in trying to change something that had been working perfectly fine for decades, they tended to set aside the very elements that made Holmes so appealing in the first place--the clever mysteries and the astounding ways in which he managed to deduce what was really going on armed with little more than his extraordinary intelligence--with a lot of stuff that was definitely new but which could hardly be considered to be improved.

Considering that the character has been off American movie screens for more than 20 years--though he has been a staple of British television dramas in the ensuing years--it is perhaps not surprising that the makers of “Sherlock Holmes” would want to do something brash and bold as a way of reintroducing him to contemporary audiences and to say that this is not your father’s Holmes (or grandfather’s, for that matter) is perhaps the understatement of the year--the intellectual and decidedly reticent sleuth has been reinvented as a flamboyantly eccentric weirdo who is as likely to solve a case with his fists than with his mind and reinterpreted by none other than Robert Downey Jr., a casting decision that has struck some as the height of genius and others as the height of sheer lunacy. The result is a broad and brawny action comedy that is most certainly unlike any other Sherlock Holmes film that has ever graced the big screen. The trouble, however, is that while it is definitely different, most of the changes don’t really improve things in any significant way and by about the halfway mark, it essentially transforms itself from a Sherlock Holmes movie into just another anonymous Hollywood blockbuster that more or less wears out its welcome long before it ends.

As the film opens, Holmes and Watson (Jude Law) are in hot pursuit of Lord Blackwood (Mark Strong), a nobleman accused of killing a string of young women in a ritualistic manner involving black magic. After an extended fight scene, they apprehend Blackwood and he is quickly sentenced to death, although he ominously pronounces at the gallows that “Death is only the beginning.” Without a case to devote his time and intellect to, Holmes quickly falls into a rut that sees him testing scientific theories in ways that generally leave his pet dog unconscious, getting into bare-knuckle brawls at the local Ye Olde Fighte Clube and trying to figure out a way of separating Watson from his fiancée (Kelly Reilly) before she can spirit him away for good. Luckily for him, if no one else, Blackwood quickly manages to somehow rise from his grave and begin a series of diabolical and seemingly impossible murders designed that will allow him and his followers to seize control of Parliament and eventually reclaim America for the British. Naturally, Holmes and Watson (who was the one to pronounce Blackwood dead at his execution in the first place) are on the case to stop his plans before it is too late and uncover how he was able to rise from the grave and commit the murders. As if that weren’t complicated enough, Holmes also has to deal with the sudden--perhaps too sudden--return of Irene Adler (Rachel McAdams), a mysterious con woman who has managed to get the best of him on a couple of occasions in their shared past and who seems to still have a few mysteries up her pretty sleeves.

“Sherlock Holmes” was directed by Guy Ritchie, the British filmmaker who garnered a significant cult following on the basis of his first two efforts, the quirky caper films “Lock, Stock and Two Smoking Barrels” and “Snatch,” and then proceeded to squander virtually all of the goodwill he had accumulated with such dreadful and increasingly tedious follow-ups as his remake of “Swept Away” and such tired rehashes of past glories as “Revolver” and “Rocknrolla.” Despite the fact that he has been better known for his marital status than his filmmaking skills over the last decade, he managed to land the job of kicking off what Warner Brothers is presumably hoping will be a new franchise and the results are pretty much a mixed bag. With this film, he is working on a scale much larger than he has ever attempted before and unlike a lot of low-budget filmmakers suddenly bumped up to the big time, he seems mostly at home with his new surroundings--he maintains the energy and wild stylistic flourishes of his previous work while skillfully integrating the contributions of such skilled veteran collaborators as cinematographer Phillippe Rousselot, production designer Sarah Greenwood and composer Hans Zimmer. This is easily the best thing that he has done in years and serves as a reminder that beyond all the tabloid headlines is a skillful and efficient filmmaker who knows how to make a broad and brash entertainment when he sets his mind to it.

The problem is that all of his cinematic skills aren’t enough to cover up the fact that the screenplay by Michael Robert Johnson, Anthony Peckham and Simon Kinberg is pretty much a wash from the get-go. Although some have complained that having Holmes engaging in shirtless fisticuffs and flirtations violated the core of his character, these elements aren’t that off-base after all--Holmes was described in the original stories as being an adept pugilist and the character of Irene Adler does appear in a couple of the Conan Doyle stories. No, the trouble is that once the decision was made to recast him in more of an action hero mold, the various screenwriters apparently decided that this was such a bold idea that they didn’t need to actually come up with a mystery--the very thing that most people come to expect from a Sherlock Holmes film--for him to solve. Instead of giving viewers the pleasure of watching Holmes as he slowly and cleverly teases clues and suppositions seemingly out of thin air, the story has him running around London dodging explosions and evil henchmen for most of the running time and then just explains everything away in a rush before heading off to the inevitable climactic fight scene high over the streets of London. The other major flaw of the screenplay is that it has no idea of what to do with the Irene Adler character--she keeps flitting on and off the screen without much rhyme or reason--and as it turns out, she is only there to offer a laborious and fairly unnecessary set-up for the all-but-inevitable sequel. The ingredients for a good story are there, I suppose, but this is the kind of committee-driven narrative that would have most likely been greatly improved by either a few more rewrites or a few less.

However, just as he did with “Iron Man,” Robert Downey Jr. rescues another third-rate screenplay with a first-rate performance that causes you to forgive (or at least forget) most of its storytelling sins. Although he may not strike most people at first glance as being the ideal embodiment of Sherlock Holmes--especially when they get a load of his simultaneously buffed-up and scruffed-out appearance--his combination of keen intelligence and sly humor gradually begin to work their magic and before too long, he takes over the role so thoroughly that you can’t imagine any other actor working today who could pull off the trick of portraying such a familiar character in such an idiosyncratic manner. (The only hiccup is that the British accent he employs is sometimes so comically thick that it is difficult to decipher.) Although the other actors are largely straight men for Downey’s antics, they mostly do so in colorful and entertaining ways--Law is pretty amusing as Watson and his byplay with Downey offers up some of the most amusing moments, Eddie Marsan is effectively irritating as the police inspector who seems to exist only to be proven wrong by Holmes and Mark Strong is nicely malevolent as Lord Blackwood. The only weak link in the cast is Rachel McAdams as Irene, though most of her problems seem derived from the flawed nature of her role--she seems as baffled with the character she is supposed to be playing as we are and never quite gets

I guess that when it comes right down to it, whether you like or dislike “Sherlock Holmes” will depend to a great deal on what kind of movie you are hoping to see when you settle down in your seat. If you are looking for a broad action comedy that does roughly for Victorian-era mysteries that “Pirates of the Caribbean” did for swashbucklers--i.e. jazz up a seemingly moribund genre with flashy special effects and a truly singular central performance from an actor who is clearly having a blast going way, way over the top--then it should prove to be an entertaining enough diversion. If, on the other hand, you are the type of person who goes to a Sherlock Holmes movie expecting a reasonably convincing movie, not even Downey’s exertions are going to keep you from feeling somewhat disappointed with its failings on that end. Despite my fondness for Downey’s performance and Ritchie’s energetic direction, I ultimately can’t quite recommend “Sherlock Holmes” because of its inability to come up with a story worthy of its central character. That said, nearly all the elements are in place for a really good Holmes film and as long as the filmmakers can improve matters in the screenplay department, I wouldn’t necessarily mind seeing a follow-up in a couple of years. Besides, at the very least, “Sherlock Holmes” is infinitely better than the likes of “Young Sherlock Holmes” and you certainly don’t need to be a master sleuth to figure that one out.